How do you get your toddler ready for flouride toothpaste? How do you know when he / she is ready?

I don't think Maiya is ready yet, but our friends bought her a gift- of a toothbrush and "toddler" toothpaste. It's for 2+, so I understand why they got it for her... And honestly, I think it's one of the most awesome gifts EVER! I just don't feel she's ready. The problem is, she LOVES this toothpaste. It was a gift from her friends! So she BEGS to brush her teeth with it all the time...

She KNOWS she's not supposed to swallow, and she knows she is supposed to spit, and she tries... She really truly tries. She goes through the motions. I just get the feeling she is swallowing a lot more than she should. I mean, I barely put any on in the first place, but I still worry.

But how do I tell? She does spit SOME out, it just seems like not as much as there should be.

Am I being paranoid? Should I not allow her to use it until I'm more confident? That would bring tears!! And if I tell her she can't use it until she's better at not swallowing and at spitting, how do help her to practice?